Convert Terraform Module Calls to JSON

Terraform Module Calls

Module blocks reference reusable Terraform configurations. They specify a source (local path, registry, or Git URL) and pass input variables to the child module.

HCL Module Definition

module "vpc" {
  source  = "terraform-aws-modules/vpc/aws"
  version = "5.1.0"

  name = "my-vpc"
  cidr = "10.0.0.0/16"

  azs             = ["us-east-1a", "us-east-1b", "us-east-1c"]
  private_subnets = ["10.0.1.0/24", "10.0.2.0/24", "10.0.3.0/24"]
  public_subnets  = ["10.0.101.0/24", "10.0.102.0/24", "10.0.103.0/24"]

  enable_nat_gateway = true
  single_nat_gateway = true

  tags = {
    Environment = "production"
    Terraform   = "true"
  }
}

module "security_group" {
  source  = "terraform-aws-modules/security-group/aws"
  version = "5.1.0"

  name        = "web-sg"
  description = "Security group for web servers"
  vpc_id      = "module.vpc.vpc_id"

  ingress_rules       = ["http-80-tcp", "https-443-tcp"]
  ingress_cidr_blocks = ["0.0.0.0/0"]
}

JSON Structure

Modules follow the standard block-to-JSON mapping: module > module name > attributes:

{
  "module": {
    "vpc": {
      "source": "terraform-aws-modules/vpc/aws",
      "version": "5.1.0",
      "name": "my-vpc",
      "cidr": "10.0.0.0/16",
      "azs": ["us-east-1a", "us-east-1b", "us-east-1c"],
      ...
    },
    "security_group": {
      "source": "terraform-aws-modules/security-group/aws",
      ...
    }
  }
}

Module Sources

The source attribute accepts multiple formats:

• Registry: "terraform-aws-modules/vpc/aws"
• GitHub: "github.com/org/repo"
• Local: "./modules/vpc"
• S3: "s3::https://bucket/module.zip"

All are represented as strings in both HCL and JSON.

Cross-Module References

References like module.vpc.vpc_id are expressions that Terraform resolves. In JSON, they appear as strings.